Bindings with key sequences - tmux

Question

Does Tmux supports key-bindings with key sequences like Vim does (e.g. bind-key ab kill-pane)? Or how can i emulate that?

Answer 1

I'm using tmux 2.3.
You can emulate key sequences by defining your own key tables and chaining them together.
For example, if I want <C-q>x to do something, I put the binding for 'x' into a key table "my-keys", then bind the key that activates that key table with switch-client (C-q):
bind-key -Tmy-keys x send-keys "my binding"
# Multi-key prefix for custom bindings
bind-key -Troot C-q switch-client -Tmy-keys
NOTE: I started with C-q, because it seems to conflict the least with the command line and Vim.
So, now you have every key at your disposal with a C-q prefix.
If you want more keys in your sequence, add another level of indirection:
bind-key -Tmy-keys x send-keys "my binding"
# Pane (i.e. 'W'indow commands like Vim with C-w)
bind-key -Tmy-keys-window-ctl s swap-pane
bind-key -Tmy-keys C-w switch-client -T my-keys-window-ctl
# Multi-key prefix for custom bindings
bind-key -Troot C-q switch-client -Tmy-keys
So, now I have swap-pane bound to <C-q><C-w>s.
This works because
<C-q> activates "my-keys" key table,
which has the binding <C-w>,
which activates "my-keys-window-ctl" key table
which has the binding s to call swap-pane

Answer 2

Tmux supports only single character key bindings (unfortunately).
So, only this:
bind-key a kill-pane
or this:
bind-key b kill-pane
Please note this is different from for example C-a (Ctrl-a) or M-a (Alt-a).
Even though we users write those with multiple characters and even have to press 2 keys to invoke them, both Ctrl-a and Alt-a are actually a single character for tmux (and in general to my knowledge).
Alternative
...might not be what you expect, but here it is:
# in .tmux.conf
bind a command-prompt -p "pressed a" "run '~/my_script %%'"
And the example my_script file:
#!/bin/bash
case "$1" in
b)
tmux kill-pane
;;
c)
tmux kill-window
;;
esac
Now after you reload your tmux.conf and press prefix + a you'll get a tmux prompt saying 'pressed a'.
Go ahead and press b and Enter. tmux kill-pane from the script will execute.
Similarly if you press prefix + a + c and Enter you'll execute another option from the script.
This kind-of mimics what you want with the addition of Enter key at the end.
Also, the provided script is extendable so you can add more "bindings" to get prefix + a + d + Enter etc..